--- /dev/null	2017-01-22 10:16:57.869617664 -0800
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.lir/src/org/graalvm/compiler/lir/ControlFlowOptimizer.java	2017-02-15 17:05:17.348136452 -0800
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2009, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.graalvm.compiler.lir;
+
+import static org.graalvm.compiler.lir.LIR.verifyBlocks;
+
+import java.util.List;
+
+import org.graalvm.compiler.core.common.cfg.AbstractBlockBase;
+import org.graalvm.compiler.debug.Debug;
+import org.graalvm.compiler.debug.DebugCounter;
+import org.graalvm.compiler.lir.gen.LIRGenerationResult;
+import org.graalvm.compiler.lir.phases.PostAllocationOptimizationPhase;
+
+import jdk.vm.ci.code.TargetDescription;
+
+/**
+ * This class performs basic optimizations on the control flow graph after LIR generation.
+ */
+public final class ControlFlowOptimizer extends PostAllocationOptimizationPhase {
+
+    /**
+     * Performs control flow optimizations on the given LIR graph.
+     */
+    @Override
+    protected void run(TargetDescription target, LIRGenerationResult lirGenRes, PostAllocationOptimizationContext context) {
+        LIR lir = lirGenRes.getLIR();
+        new Optimizer(lir).deleteEmptyBlocks(lir.codeEmittingOrder());
+    }
+
+    private static final class Optimizer {
+
+        private final LIR lir;
+
+        private Optimizer(LIR lir) {
+            this.lir = lir;
+        }
+
+        private static final DebugCounter BLOCKS_DELETED = Debug.counter("BlocksDeleted");
+
+        /**
+         * Checks whether a block can be deleted. Only blocks with exactly one successor and an
+         * unconditional branch to this successor are eligable.
+         *
+         * @param block the block checked for deletion
+         * @return whether the block can be deleted
+         */
+        private boolean canDeleteBlock(AbstractBlockBase<?> block) {
+            if (block == null || block.getSuccessorCount() != 1 || block.getPredecessorCount() == 0 || block.getSuccessors()[0] == block) {
+                return false;
+            }
+
+            List<LIRInstruction> instructions = lir.getLIRforBlock(block);
+
+            assert instructions.size() >= 2 : "block must have label and branch";
+            assert instructions.get(0) instanceof StandardOp.LabelOp : "first instruction must always be a label";
+            assert instructions.get(instructions.size() - 1) instanceof StandardOp.JumpOp : "last instruction must always be a branch";
+            assert ((StandardOp.JumpOp) instructions.get(instructions.size() - 1)).destination().label() == ((StandardOp.LabelOp) lir.getLIRforBlock(block.getSuccessors()[0]).get(
+                            0)).getLabel() : "branch target must be the successor";
+
+            // Block must have exactly one successor.
+            return instructions.size() == 2 && !instructions.get(instructions.size() - 1).hasState() && !block.isExceptionEntry();
+        }
+
+        private void alignBlock(AbstractBlockBase<?> block) {
+            if (!block.isAligned()) {
+                block.setAlign(true);
+                List<LIRInstruction> instructions = lir.getLIRforBlock(block);
+                assert instructions.get(0) instanceof StandardOp.LabelOp : "first instruction must always be a label";
+                StandardOp.LabelOp label = (StandardOp.LabelOp) instructions.get(0);
+                instructions.set(0, new StandardOp.LabelOp(label.getLabel(), true));
+            }
+        }
+
+        private void deleteEmptyBlocks(AbstractBlockBase<?>[] blocks) {
+            assert verifyBlocks(lir, blocks);
+            for (int i = 0; i < blocks.length; i++) {
+                AbstractBlockBase<?> block = blocks[i];
+                if (canDeleteBlock(block)) {
+
+                    block.delete();
+                    // adjust successor and predecessor lists
+                    AbstractBlockBase<?> other = block.getSuccessors()[0];
+                    if (block.isAligned()) {
+                        alignBlock(other);
+                    }
+
+                    BLOCKS_DELETED.increment();
+                    blocks[i] = null;
+                }
+            }
+            assert verifyBlocks(lir, blocks);
+        }
+    }
+}